In many fields of industrial production, a spray application of viscous or highly viscous fluids can be used, for example in the car industry when applying sound absorption mats or for seam sealing. The application of adhesives can also be a field of use for the spray application.
A corresponding application system can include a metering device, a hose connection, an application nozzle, and a fluid valve situated close to the application nozzle in terms of fluid mechanics. With the fluid valve, the fluid duct which can be formed by the specified components can be selectively interrupted between the metering device and the application nozzle in order, for example, to help prevent the fluid from dripping out of the application nozzle when the metering device is switched off. This brings about coordination of the switching on and off of the metering device and fluid valve in order, for example, to avoid a situation in which the metering element can be switched on while the fluid valve is still closed, which can bring about a rise in pressure.
Due to the high viscosity of the material to be applied, the application of the material should be occur under high pressure, for example, by using a metering cylinder with a servo drive. However, those skilled in the art can be aware of further embodiments of metering devices, for example, gear pumps or spiral pumps, wherein a servo motor cam also frequently serve as the drive here. The hose connection between the metering cylinder and the application nozzle is to be configured as a high-pressure hose. An application system therefore has a dynamic behaviour which can be dependent on a number of factors, for example, the extensibility of the hose, the rotary masses of the drive of the metering device and delay times, for example, during the switching on or off of the metering device or the switching on or off of the fluid valve. However, the type of viscous fluid to be applied can also include an influence on the dynamic behaviour of an application system, and wherein charge fluctuations of the viscous fluid can also have an influence on the dynamic behaviour.
The final geometric shape of the viscous material which is applied to the surface of an object under high pressure by an application nozzle can be dependent on the width and homogeneity of the spray jet, the speed at which the application nozzle is moved over the surface of the object to be sprayed, for example, a robot, and the respective volume flow through the application nozzle. Due to a linear movement of the application nozzle, the viscous material can be applied in a strip-like shape to the surface of an object.
A layer thickness which is as homogeneous and a constant width of the applied material strip are usually desired, wherein the width of said strip is dependent to a high degree on the volume flow of the fluid through the fluid duct of the application system during the application process. However, after a change in the input parameters of the application system, on account of the high dynamics, already mentioned, of such an application system, for example, the flow volume can be subjected to certain dynamic fluctuations which can also bring about a deviation, for example, of the actually applied strip width from the desired strip width.
In order to improve the dynamic behaviour of an application system, the input parameters of the application system, such as, for example, the rotational speed predefinition of the drive, can be fed, before its application, to a pre-processing stage such as a filter and thereby adapted. Given a corresponding selection of the process parameters of the pre-processing stage, or of the filter parameters, the dynamic behaviour of an application system can be improved.
The determination of the such process parameters on the basis of measurement technology can prove to be very complex and subject to faults. Known through-flow meters have to be integrated into the fluid duct in order to measure the volume flow and can influence the dynamic behaviour thereof, with the result that process parameters which are determined based on such a measurement can be imprecise. A further exemplary embodiment of the estimation of such process parameters or the empirical determination thereof can prove to be very time-consuming and likewise imprecise.